Molecular dynamics simulation of a binary mixture lubricant for use in hard disk interfaces

Document Type : Reasearch Paper


Department of Mechanical Engineering, Pondicherry Engineering College, Puducherry – 605 014, India.



In Hard Disk Drives (HDD), it is necessary to decrease the Flying Height (FH) between the head and the disk (currently, FH is around 3-5 nm) so as to increase recording densities. Retaining the solid lubricant has become a difficult proposition owing to intermittent contact between the surfaces. ZTMD and Z are used as solid lubricant to lubricate these interfaces. In this paper, the behavior of the binary mixture lubricant such as ZTMD & Z is modeled and analyzed using Molecular Dynamics (MD) simulation with the help of GROMACS software. It can be observed from simulation studies that ZTMD has poor replenishment performance although it possesses good retention properties. Addition of Z molecules improves replenishment performance of whole system. When ZTMD molecules alone are modeled, final structure attains stable state only at -4800 kJmol-1. After the addition of Z molecules, final structure (ZTMD+Z) attains more stable state at -6950 kJ mol-1. When compared to ZTMD, binary mixture lubricants (ZTMD + Z) are considered as more stable and for use in HDDs for their efficient operation.